The best replacement for ios 5.1 is 5.0.1.

The best alternatives to ios 5.1 are rated as following:
★★★★★  5.0.1
★★★★  ios 5.0
★  5.01

Your alternative for ios 5.1 is not listed? Suggest!
Speaking about ios 5.1, one probably shouldn't forget about xcode 4.2.

Other search terms related to ios 5.1 and their ratings are:
★★★★★ xcode 4.2
★★★★★ 4g
★★★★ 3gs
★★★ gevey sim
You have in mind a companion for ios 5.1 and it is not yet here? Propose!



Google Trends

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ios 5.1
5.0.1
ios 5.0