1.6.1 First iPad Version
1.7 iPad version with terrain, please use X-Plane to see what this looks like when you have altitude:
http://www.skycharts.net/?page_id=228
1.8 Universal app of SkyChartsPro. G-Fi support.
1.9 Bugfixes for iPad 3G
2.0 Bugfixes for running out of memory when updating.
2.1 iOS4 fixes. Cached METARs/TAFs. Fix for missing METARs
2.2 More iOS4 fixes, including fast suspend/resume. Fix for random rotation of airplane icon.
2.3 Automatic nearest calculation with bearing and distance (iPad gets 20 closest, iPhone has one). ZULU time on display.
2.4 iOS4 changes. Release of both Classic&Pro. New easier chart selection, and faster download. Show current chart cycle and expiration date.
2.5 Background download. SUA information (SpecialUseAirspace). High Enroute IFR charts. Partial WAC charts to extend sectional coverage.
2.6 AirPrint support. iOS4 fixes.
2.7 Fix when updating from old version.
2.8 X-Plane fix, new Pacific region select (and charts), and Alaska low&high IFR charts. Removed G-Fi support.
2.9 Maintenance update: Updated database, less download threads to improve slow networks like DSL or Edge.
2.9.1 GUI fix for iPhone 4S
2.9.2 iOS5 fix for XPlane
2.9.3 iOS5 fix, set file attribute to avoid file deletion by iOS. Added Action button to plate viewer to allow other apps to view PDFs.
2.9.4 X-Plane 10 fix
2.9.5 Retina display support
2.9.6 iPhone5 and iOS6 updates
2.9.7 Ground speed fixes and removed iOS4.3 support
2.9.8 Easier to select charts and better search help
2.9.9 Bugfixes – the database could in some instances become corrupt first time you run the app (I wonder what changed under the hood, I haven’t changed a single line in that portion!)
3.0 Better search and add double tap info for VORs.
4.0 ARC and storyboard rewrite. This includes easier to use selection of charts, easier search, and other GUI goodies.
4.1 Subscriptions
4.2 Winds Aloft.
4.3 HSI overlay.
4.4 TFR’s.
4.5 Radar overlay.

Todo:
Add ‘GPS only’ switch (instead of using gps/cell/wifi – the latter two can be very inprecise).
Display disk usage. E6B. Cross track readout. Allow customization of GPS readouts. Colors. Icons.
Show scale of charts, or an extension of plane with NM in it. Extend Info sensitivity area.
Look into MSFSX connection.
Show breadcrumbs on map for flight so far.
GPX export. Save/restore flight plans (automatically).
Add home/favorite identifiers for quick selection.
Auto-cache.
Allow user to download everything in X miles around route.
Include winds aloft calculation in navlog.
Add more phone numbers & ILS frequencies etc to a new page with a clear airport info.
Free text search of navigation database. More options to BreadCrumbs.
Add international airports to navigation database. Decoded METAR/TAF.
Add a human readable form of lat/long instead of what’s in place now.
Showing what type of airspace currently you are using. Glide-range.
Change chart selector to avoid cycling through unwanted charts.
Automatically display airport diagram when on ground (give user choice if they want this or not).
Larger/customizable flight data readout.
Fix copy/paste issue. Build database for approach plates vs fixes.
Add MPH.
Make it easy to add holds: left/right and time or distance.
Link A/FD to tower enroute control (SoCal for instance)
Add international fixes so all low&high enroute charts can be added.
Quick select list of favorite airports/IAPs.
Import other flight planner waypoints somehow.
Add dimmer for night flying.
List frequencies for ATC in your region.
Add lock for inadvertent touches.
CAP search pattern
Save/Restore routes
Easy user select of custom waypoints on charts.
VOR check data from A/FD
Manually geo-reference approach plates and airport/taxi diagrams
Add obstacle data and highlight obstacles close by
Show navigation data on approach plate

FYI: If you have an iPod touch or an iPad wifi, you can get GPS location in a couple of ways.

These products work well:
http://bad-elf.com/products/gps/
http://www.amazon.com/GNS-5870…..B004289ZW0
http://www.amazon.com/Dual-Ele…..038;sr=8-1

You can also jailbreak your device and add an inexpensive GPS bluetooth receiver.
For the iPod touch the RoqyBT reportedly works.
For the iPad wifi the BTstack reportedly works.

FYI: You loose your warranty if you jail-break. Please be careful!