Lemur allows you to turn your device into a fully customizable MIDI control surface. Lemur has more features which makes it a lot more powerful than TouchOSC.
However, this functionality comes at the cost of complexity and makes Lemur harder to get started with. But if you want to make sure you have every single control option available, it is the most powerful control software you can have.

TouchOSC allows to remote control and receive feedback from software and hardware that implement the OSC or MIDI protocols such as Apple Logic Pro/Express, Ableton Live, Renoise, Pure Data, Max/MSP/Jitter, Max for Live, OSCulator, VDMX, Resolume Avenue/Arena, Modul8, Plogue Bidule, NI Traktor, NI Reaktor, Quartz Composer, Supercollider, vvvv, Derivative TouchDesigner, Isadora and many others.
Mixvibes, the pioneer of digital DJing, introduces the perfect remix toolbox: lay down samples on a grid of pads and tweak them in seconds. Bringing loops and finger drumming together, it opens new creative possibilities to lay down ideas in the spur-of-the-moment.
Change the tempo, adjust samples' tone or play them in reverse mode, all in real time!

Image-Line Remote ( IL Remote ) is a free Wi-Fi MIDI controller for FL STUDIO on desktop and laptop computers. It works on Tablets or Phones. Just open FL Studio on your computer plus IL Remote on your iDevice and the connection is automatically made over your Wi-Fi network.
Control FL Studio instantly or link your favorite instrument and effect plugins just as you can with any MIDI controller. Use a phone, tablet or any combination with up to 15 devices simultaneously.