What is Reddit's opinion of AlmostTI - TI Calc Emulator?

From 3.5 billion Reddit comments

As for backups - Texas intruments have all of their calculators' OSs available on their homepage. You'll have to register an account with them, but that's all.

As for the calculator not accepting new OSs, you'll need to be more detailed than that. What calculator is it, and what error message does it give?

Also, are you allowed to use a mobile phone with a calculator app? This app emulates a variety of TI calculators on your mobile phone - the ROM is available on TI's homepage, once you register an account.

Are none of the scientific calculator apps for Android any good?

For example: AlmostTI

Run a TIcalc emulator on said phone.

https://play.google.com/store/apps/details?id=com.fms.ati

https://play.google.com/store/apps/details?id=com.fms.ati

https://play.google.com/store/apps/details?id=com.fms.ati&hl=en