Finally got time to post some new information and it is very pleasant to me.
Our product, Ganttzilla - online MPP, MPX, Planner documents viewer, finally launched!
Ganttzilla is the online project plan documents viewer which supports popular Microsoft Project and Planner formats. Using it You can view or share your Gantts with anyone using just Web Browser. Now we are only beta version but hope to improve it in the future. Will be very grateful for any comments/remarks/criticism, even bugs :)