I would even go as far as to state that any paid video converter for the smartphones is a rip-off....
Commercial companies try to seduce customers with all kinds of features trying to combine in one package, but this hardly results in a well built software. Usually, each piece of software is built to be good in certain tasks, so it is good to get separate software for ripping, converting and editing.
There is a limitation to the smartphone power at this moment, so making a very complex encoding and large files for a phone (such as AVCHD) is simply waste of time - a) you phone can't play it anyway, b) the small display will not allow you to enjoy the HD resolution video.
By the way, Phones can play MKV (and many other container formats) videos using a so called all-round players (like RockPlayer).
Nvidia Cuda (for for that matter ATI Stream) are commercial terms for using GPU power in video conversion tasks. While that sounds quite interesting, the conversion quality usually is not that good. Besides, you can't use CUDA if you don't have a proper Nvidia GPU. Badaboom was one of the first examples of such a software.
Moreover, the modern PCs come with dual/quad core CPUs and are able to process a video conversion in 4/8 simultaneous threads. I've tested the conversion speed using GPU processing power (ATI Stream GUI) and multi-thread CPU conversion. I didn't see any noticeable speed differences, while the CPU conversion resulted in a better video quality.
Anyway, if you desire to try such a thing then for example the free Mediacoder can do that for you.
Most of the free converters can do that too (Xmedia Recode, Format Factory, Mediacoder, Xvid4PSP, etc...). However, you don't need that for a smartphone. You need something that says "whatever the source video" and converts it in a MP4 container using MPEG4 standard.
Again, this is a piece of cake for most of the free converters.
Most of the editing can be done by using free software like Avidemux or VirtualDub.
