Tip setting flexibility

Twitter tipping is great. I enjoyed.
it would be better if
・we can set every amount of tip we want to send. The advantage of crypt currency is the flexibility, so only three to 15 options(e.g. 1 BAT, 5 BAT)are inconvenient.
・we can tip via smart phone, especially iPhone. I assume most people use Twitter not by PC but by mobile phone.

Thank you for your great work!