I guess it depends on what the elements of your PLE are.
For example, I often browser library databases and Google Scholar to find articles, which I then read, annotate and do something with using GoodReader (awesome app!).
I often check my Google Reader subscriptions with
Perfect RSS (and before that
byline) to read my incoming RSS feeds and share them to Twitter or my
Google Shared Items (yup, they still work! ;-) ). I've used
Pocket to save articles to read later (when I am not connected to the net) and then share them with others when I do connect to the net. Of course,
Google+ and
Twitter clients are obligatory ;-)
I only wish google Groups worked betters on Mobile.