Our need is to connect 100 BTLE tags to a single Android phone running our app.
This is out experience on this issue:
Some producers (Samsung) has written specific BTLE libraries for Android 4.2, we have never tried them.
Google, starting from 4.3, started implementing BTLE, so any previous release has been superseeded and any other producer
libraries have been abandoned.
We have tried the Samsung S3 with Android 4.3, we got a stable connection but with a 7 bonded tags limit.
On Samsung S4 with Android 4.3, the connection is not stable. Bonding would fail often and it was difficult to connect.
Unfortunately the Samsung source code is not availalbe.
We then tried Nexus 4 and Nexus 5, but on Android 4.4 the maximum bonded devices is down to 4, which is even worse.
Since the stock Android (on Nexus) do have source code available, our idea was to rewrite a simplified version of the BTLE library provided with Android (bluedroid) which fix this limit of bonded tags.
We can use any other 4 or 5 inches phone.
What we need is to be 100% sure that the person who take this project do fully understand what we require of him and is capable to complete it.