As reviewed by other people. The app just doesn't allow users to send messages while on lower data speed. Its just disgusting. While ath the same time you open other messenger apps like whtasapp and send a message they just manage to send the message within 5 or 10 second. While in signal the message keeps on sending and sending and takes upto 15 or 20 minuets. please fix this issue to and optimize the message sending.