The problem CoWallEth - Cold Wallet Etherium solves

Our Objective is to provide Mobile application and a hardware wallet to securely store private keys offline using contactless NFC technology combined with symmetric encryption algorithm. Here users do not have to store their private credentials into any third party server and can manage all transactions directly using NFC card.

90% of hacks happen from centralized exchanges as they manage users private keys which is more insecure and vulnerable to attack and storage of keys depends upon their free will and no one can enforce it.
100’s of application will have file access on local device hence storing private credential in a local system may also lead to vulnerability and loss of private keys.
The Best solution is a Hardware wallet but even that is often quite expensive and difficult to carry around.
Our choice is a cost-effective, user-friendly, contactless and secure option to store the data in a credit card-sized NFC card which solves most of the above problems.

Challenges we ran into

We ran into so many obstacles while developing this solution like:-

1. We wanted a native application for more secure and seamless operation.
2. There was almost no working documentation to refer to for native android experience and we had to do a lot of trial and
   error and find and file bugs.
3. NFC integration seems easy but can act weird in so many ways that we had to deal with.