Virtual MIDI Piano Keyboard is a MIDI event generator and receiver. It doesn't produce any sound by itself, but can be used to drive a MIDI synthesizer (either hardware or software, internal or external). You can use the computer's keyboard or mouse to play MIDI notes. You can use the Virtual MIDI Piano Keyboard to display the played MIDI notes from another instrument or MIDI file player.
RC Flyers Toolkit Box is a handy toolbox for R/C pilots. It helps you manage batteries, flights, charge cycles, and check lists. It helps you keep track of which of your batteries are charged, where and when you have been flying last, how much went in your battery compared to the last cycle, what you have to pack to take with you, and which parts you have to check before flying. For rotary wing users, there is a pinion calculator that quickly gives you an idea about the RPM to be expected.