Just a couple of minor points.
1. The App in question is not so people can maintain a list of what sins they feel they committed, rather it is to help them examine their conscience so they are reasonably certain to confess all the mortal sins they have committed.
2. Using such an application would not be in itself a sin. No Catholic is obligated to keep their own confession silent only their confessor is.
3. The Church never tried to ban reading and writing. There is quite a bit of folk lore that developed around a couple of things. The first was that the Bible was often chained down in Churches. Bibles at the time were copied by hand, and as a result were incredibly expensive. Thus the Bible was chained down to protect it from theft and damage. The second was the Church's prohibition on unauthorized translations of the Bible. In an era before copyright, the Bible was essentially the one copyrighted book.. and the Church was the copyright holder
. It got cranky with people using its intellectual property for profit (particularly considering that many of those early translations were not very good!).
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Bill