There are many online places to read the Bible. Here are some that I recommend:
One of the largest collection of bible translations, including some non-english versions. You can easily have multiple translations in parallel. If you want to see how Mark 1:1 is translated check out this link.
A large selection of bible translations. Good support for your phone.
I use this for the NET translation and access to Greek and Hebrew.
A good collection of translations and resources, the interface is a little out of date.
A limited number of translations.
If your main goal is to compare English versions, BibleGateway is your best option. YouVersion offers a few more versions, but you can only compare two at a time. If you have some knowledge of Greek and/or Hebrew, I like the Lumina Bible best with its sympathetic highlighting.