CustomKeys Programmable Calc gives you full control over your calculator layout. 8 programmable keys for any number or function — square root, percentage, VAT multiplier, MEM key. Drag & Drop to rearrange keys, flip for left-handed use, color-code any key. Built-in geometric shape calculators for circle, triangle, square, rectangle and more with formulas. Sound & vibration feedback. Dark mode. One-time purchase, no ads.