Illformed's first generation of 'Glitch', aka 'deep blue glitch', may be discontinued but I still use it constantly. In fact, it's featured in several BeatWav sample packs. Those little stutters, retriggers, crushed bits and tape-stops are often the result of getting creative with this plugin. You'll need a 32-bit bridge but Reaper comes standard with one. Illformed has released 'Glitch 2' at this point and it's certainly worth the purchase but you can't beat free and 'Glitch 1' is free. Just click here.