A number of changes to Strava and MongoLabs meant the x2G app stopped working last year. I thought I would have a new app out that absorbed the main functionality of x2G however that is taking longer than expected, so I went back and fixed the number of issues it had. So it should be working again!
My new app will synchronise to-and-from Google Calendar so will be a natural progression when it comes out.
As for Nike+GPX, I don’t use Nike+ anymore so didn’t notice it too had some issues which I see a few people have written updates to handle. So I have made it open source on GitHub now (https://github.com/jkili/nike-gpx), I should have done that a long time ago. So please feel free to keep the plugin up-to-date and I will post updates here when required.
Update 16/Mar/2016: NikePlus Plugin has been updated in both the download link and Chrome Web Store to v0.48 (Thanks to Per Jensen & Matthias Hüller). GitHub also merged.
Continuum 
Hello!
Attempting to download my running data with the Chrome extension NikePlus Exporter I got the message:
An error occurred while creating GPX file. Details: [TypeError: Failed to execute ‘createDocument’ on ‘DOMImplementation’: parameter 3 is not of type ‘DocumentType’.]
What should I try now? Thank you!
I think someone has fix this. Look through the comments and find the download link. I will incorporate his fix soon.
Hello, I have some problem with the use of app.
When I log on Nike+ and I try to download a gpx or tcx file, I have this message :
Error!
An error occurred while creating GPX file. Details: [TypeError: Failed to execute ‘createDocument’ on ‘DOMImplementation’: parameter 3 is not of type ‘DocumentType’.]
What can I do ?
I’m on Windows 10 64 bits.
Thank you.
S PHILIP
The download link has been updated. Please try again.
Link updated now.
Hi, thank you for the great program. however whenever i’m trying to download runs i keep getting this message – Error!
An error occurred while creating GPX file. Details: [RangeError: Invalid time value]
Is this an error anyone else has got? Thank you