iFormula - Your Own Calculator

I purchased this app because I am in the directional drilling industry. I was able to write some of the common formulas that I use every day into it and so far it is working great! Anyone who uses angles like co-sign, sine and tangent formulas should know you have to write the angle and then convert to radiaons. Us tang(angle*PI/180) it’ll work well. Very good so far and exactly what I needed. A variable based formula saver.

I was using this app and THREE things made be delete it. 1. It asks a bunch of stuff at the beginning and even to upgrade to v 2.5. Wouldn't we already have that? 2. The question mark tells you how to make a formula, but you can't get out causing you to have to get out of the app and get back on, WHICH CAUSES YOU TO LOSE ALL OF YOUR PROGRESS. 3. The formula maker only shows 1 input field/constant field. Not helpful at all. Please fix this stupid app.

Does everything you need to write your own formulas.