...
Personally, I would rather have the option normal, quick, super quick confirmations than an app asking me the exact amount of satoshis to use for a transaction. Far often than not, I have to put up with people picking an amount next to nothing and then bitching for 24 hours that their transaction isn't confirmed.
People complain that bitcoin is too complicated, but when made easier, they complain about not being able to control it to the point where it's not usable.
Using language like "normal", "quick" and "super quick" is a "Bad Idea"™. As that would be setting user expectations without being able to guarantee you could actually deliver. Even the use of "Low-Prio" and "Priority" is a bit iffy as there are no guarantees with BTC.
If you use the "Super Quick" value... and then 30,000 transactions get dumped onto the network that all have double your fee... how "Super Quick" do you think your transaction is actually going to be? Then you will have all the users who don't understand BTC and the blockchain properly, moaning that your wallet is too slow and X wallet is much faster.
And if you think I'm being unrealistic, check out
the historical mempool count... There are massive spikes all the time.
Honestly, I think the best solution is just provide "advanced" settings, that would let the user specify. Electrum on the desktop lets you do it... if you want, otherwise you can just use dynamic and it will try and calculate the "best" fee according to their algorithm. The Electrum Android client lets you specify the fees in the settings, but has a minimum of 0.0003 BTC/kB (~ 30 sats/byte) and a max of 0.0003 BTC/kB (300 sats/byte) going in 0.0003 increments (or you just use the Dynamic option, which I believe takes fee estimates from the Electrum server)
Mycelium could easily just incorporate a "fifth" option on the fee level button that says "Manual" and enable a textinput box that would let you just enter an amount. Maybe throw up a toast message warning if it is below what it considers to be "normal".
I've been looking at the code on github, and would give it a shot, but I don't have access to an Android build environment to try it