I want my app to be able to create addresses and be notified when an address receives a deposit. What I've tried so far doesn't work reliably enough.
I've tried the Coinbase API (address callbacks didn't seem to work at all) and Blockchain.info (sometimes it works fine, but usually it takes several minutes to several hours for the callback to fire).
Are there other APIs that offer address creation with callbacks that don't involve running my own Bitcoin client, or is running your own client pretty much a necessity for reliable notification (within seconds)? Is anyone actually using Coinbase or Blockchain successfully? My service would need rather immediate notification of transfer (number of confirmations isn't important).