Droidin - If you are a LinkedIn user and an Android owner you know that there was not a good app from LinkedIn until rather recently. Before that there was DroidIn. It still is a good app if you are a mobile LinkedIn user.  It has your inbox, updates, contacts and now groups.  It is fast and uses the open API and is not just a web page link.  You can also sync your contacts with the built in Android contacts.  This is a great alternative to the LinkedIn app.  

https://market.android.com/details?id=bostone.android.droidin&feature=search_result#?t=W251bGwsMSwyLDEsImJvc3RvbmUuYW5kcm9pZC5kcm9pZGluIl0.