Incredibly Simple I have a TI-89 Titanium which i use all of the time, but generally when i need it in any actual applications, i never have it in my bag and am forced to resort to my phone calculator. Standard Calculators just never cut it for me. Yet with this app, while i still love physically owning a TI-89, guarantee's i'll never be without it even if the actual device isn't with me. Excellent App! This is truly using the capabilities of a smart phone!

Very Good I used a 89 when in my calc class long ago. I do math as a hobby now, but didnt want to buy another calculator for the purposes of having some fun with math. So far i see the 89 run flawless, however i see some quirks with the 89 titanium rom. I tried the titanium first, but removed it and installed the 89 rom instead. Still i think its a great emulator. You can get the roms from ti website

Best calculator ever I just realized that after over a year of using it, I still haven't given this app a five star rating! So here it is. I'm a physics major, still in school, and I use this app nearly every day, and I've got to say, out of all my most frequent apps, this is the app that's given me the least sass. Even stock Android apps crash more than this app. Thanks! (P.S. I prefer the titanium edition, it's a very good looking layout, and would definitely recommend using that one over the normal layout)

Stoked. Great emulator I had been looking for a calculator app for android that could do the things my old ti-92 could do. Was very surprised there really was nothing with all that functionality. But this emulator does the trick. Why change of habits when you can put old software on new hardware! Thanks so much!!

Oh My This app makes me want to go back in time. I would go to my 5th grade teacher and ask "why can't I use a calculator?" and when the robotic response came "You won't always have a calculator with you!" I would punch her in the face. I mean seriously, I saw this coming 32 years ago when I was 10. I LOVE this app because I loved my TI89! And it is ALWAYS with me...take that Ms. Chatterton!

I love it! Just like my 89 titanium. I love that the buttons are exactly like the actual calculator. Of course it is a little skewed, but it has to be to fit everything on the screen. I think it is great and I am very happy to have it. Great job! Ignore the people on here that don't know how to load a ROM (or follow simple directions). Also, if you have a Ti-89, you would know how to exit the app properly.

A Most Excellent App I just started my dabbling, and to say it succinctly, this app/emulator is a mirror of TI's line of graphing calcs, and a very stable one at that. The one thing to add I can think of is the ability to install apps(and from what I saw it's already suggested). But until then, I'm going to play with the software and check out loading the apps into a ROM via the emulator/TI's dev tools on the PC, when I've got time. Two thumbs, an outstanding app! You'll never have to use your abacus again!

Excellent All Around Got this going in no time at all thanks to TI having a free download of their 89 rom. Played with it for a while and it runs beautifully! Only problem I've seen is a lot of flashing on the screen playing assembly games, (my primary use for my ti-89 in calculus class was games... (: ) Any idea what causes that? I'd love to play calcrogue again... but it's giving me a headache, lol!

Just like the real thing! A lovely emulation of the real calculator. My personal favourites are HP RPN calculators but all of these emulations preserve classic calculators that we can use even though our original ones may no longer work. Well done!

Great. Really. I love my TI89. I've still got my school TI89. It's resting in a drawer. Without brain, though, so to speak, as it's lending its ROM to my S5. As a student I thought the TI89 is a device to carry with me always, because you never know what situations you might get yourself into some sunny day... possibly an instable tesseract that affords complex calculations to escape before it collapses ;) Now, with this app I've finally got it in my pocket really ALWAYS, wherever I go. That's great. Really. :)

Excellent! I lost my 89 a couple of months back, but this is an excellent substitute! I am a college student that only uses a calculator outside of an exam situation. This is an excellent at-home calculator, especially if you need access to the log function, sine, cosine, etc.

Bare minimum emulator This app has so much potential, but I feel like it falls flat. Suggestions: we all know what it looks like, can we have an option for a button grid, rather than buttons with dead space around them? Also, make the text on the buttons (in grid form) change with the pressed function keys. Make the screen area slightly smaller for more room for buttons. That would make it perfect in my opinion.

Works Perfectly, and Open Source To Boot! The TI-89 interface is nothing like the interface on the TI-83 and 84, and a poor reason to rate the app with one star. The CAS and 3D graphing capability alone make the calculator more advanced than the 83 and 84. Whether the 89 is better than the 83 or 84 is a matter of debate. As to the app itself, its best feature is the ability to install apps to the "flash memory" of the calculator, allowing the emulator to use the apps that come standard on the TI-89 Titanium, including the stats and list editor. A minor complaint, and one that does not merit a reduction in rating, is that the TI-89 Titanium keypad is too bright, thanks to TI using a "Titanium" finish. I've fixed this in my copy of the app, built from source.

Wow!! I can't believe I got this to work! For those who rate one star: go back to using a landline! You have no business with such an advanced device! **But with latest update the buttons aren't as responsive as they used to be but I do like the improvements especially since I upgraded to an HTC One! *2014 update: Now the keys are very responsive, I don't know how since there was no update but I'm love this app! My favorite one!

Simple & it works FYI, you don't need to have a Ti calculator to get a operating system rom. Just go to the Ti website, navigate to the downloads section of the calculator you want and download the latest version of the operating system. Put that file somewhere on your device and add the rom. That's it.

Don't like the new changes Used to be my favorite. New view looks awkward. Wish developers made overhauls like this optional to users (e.g. Classic vs. Modern mode in settings).

Fantastic emulator This is a wonderful tool. The application is extremely easy to use, even though the calculator it is emulating is a beast to wield. TI has the latest updates for the ROMs on their website, so you can quickly find and download the latest version. Easiest emulator I've ever used by far.

Best app ever You need a tablet to be able to see the buttons but if you've got one, this totally works as a graphing calculator. Helps me so much! (later edit) loses one star for the file transfer feature having problems. Won't let you upload more than one file to the calculator's memory at a time without locking up. Irrelevant bug if you dont use that feature as most people dont.

TI = $175+ & eBay = $89 But this one's FREE. Only problems are that memory is limited, and if you reset it, you lose all variables and everything you had done... I want to be able to use more phone memory, not be treated like a calc, and to be able to have all my data "archived," so my variables won't be deleted, and I want "not save on exit" to work.

Love It! I have been a long-time TI89 user, but struggled with the horribly dim LCD screen for years. Thank you so much for bringing this classic calculator to Android!

Slow typing I do not understand why my keyboard on mh samsung s5 is fast but pressing buttons on the calculator is so slow. I can't be the only one with this problem. Let me know if anyone has a solution

This works! If it doesn't work, you don't know how to use it. Download this app, which does nothing until you download the ti89 ROM from the Texas Instruments website. Open app, locate and add the downloaded file which must be on your phone somewhere. Done, fully functioning ti89 for free!

Nostalgia Makes me want to dig my 89 Titanium out of the closet and play with it again. The 89/92 series of graphic calculators were very powerful handheld machines in their time, and now we live in a world where cellphones can run them. Good work but has one problem so far, when sending a file, and it's already on the calc, then the app crashes.

I would love if... I actually own a TI - 89 Titanium calculator but it is starting to break after 10 years of usage so I was hoping this could substitute it but I cannot install any new apps as it goes into the browsing section for me to point to the file it immediately force closes I have sent a bug report will definitely change to 5 stars when fixed. It also force closes when I enter the configuration menu

Amazing It works great much better than spending a bunch of money buying a new 89 after someone stole my old one. It's a little weird on a touch screen but you get used to it fast. Also TI has the ROM free on their website so just download it and you are ready to go!

Works great, but lacks a few features The app itself works very nicely, although I would like to see support for the stat-/list-editor. Also, the icon is very low res and not that pretty.

Amazing Once we can load calc programs it would be 6 stars. Only critique, can you turn off the phones back button when the calculator app is open so we dont close out by mistake when trying to press the enter key on the calculator?

Very good implementation If only Texas Instruments did provide a way to purchase a copy of the ROM legally, this might be even better than the real hardware. Obviously one gets better haptic feedback with real buttons but otherwise emulated hardware is better (better screen viewing angles, possibly better performance than with real hardware).

Possibly my favorite app of all time I have owned and loved two TI 89's since 1999 or so, and was delighted to discover this emulator. I still get tickled when I open it and think how far technology has come.

Full-Featured Very helpful when I don't have my TI-89 on hand. It even allows you to install applications, just as you would on a physical device! Very usable on my Note 2's large screen.

OK. Buttons are a bit unresponsive, have to hold a bit before they respond. But I love how fast it calculates and graphs things. An actual calculator graphs things painstakingly slowly.

Never leave home without it. Not hard to setup and is one of the most useful calculator emulators. TI-89 Titanium works flawlessly on Samsung Galaxy S5.

TI89 great emulator best emulator for TI89. I use this much more than any pc emulator because the touch screen is so much more natural. for the person longing for their TI89 this is great. I use it more than my actual TI89 because it has no backlight.

Great for students I tutor math and I recommend this to all my students. Most professors won't allow you to have a phone in a test, but this is great for homework!

This is my primary calculator A little annoying to extract the Rom from a physical calculator but will worth it. It's a shame there isn't a native calculator app that is this good.

Needs updating for newest devices? Doesn't work with 2013 KitKat nexus 7? To bad, works great on my old galaxy s2.

Saved me $150! To fins the ROM search "ti-89 titanium texas instruments." Go to the Texas Instruments site and download the TI-89 Operating System (OS) and that's your ROM. They may prompt you to aet up an account with them. It's harmless to do so and easy.

Bought the paid version Great app. Recently open sourced and added support for firmware upgrade files. You can just search for the operating system of the calculator you own and download it on TI's website. Great!!!

Please make a widget if possible. This app is great! It was just what I was looking for: advanced computing on my phone. My only suggestion is make a 4x4 widget for my home screen! I am not sure of the feasibility of this given the app is emulating the OS on the calculator but it sure would be nice.

Love it. Just upgraded to the paid version. Been using this one almost since it came out. Felt like I owed the developer, so... ya...