[Android Apps and Games] Bexton:
That's odd. But I checked back and according to the Manifest version 1 support schedule, the support for v1 extensions is not yet dropped - unlike I said in OP. According to the schedule the support will be dropped in "early 2013". Thus, APK Downloader v1.2.1 should still work as it did all the time; also with the latest Chrome versions. Now, to explain you why I said/thought it was:

The thing is that I used v1.2.1 almost every day and I never had problems to download Apps, except for a few that were labeled as non-compatible with my devices in the play store. (I will come back on that later..) Then, a few days ago, the extension just stopped working without me making any changes. So I opened Chrome's developer console and saw that the extension threw some content security policy errors fired by the extension's Javascript code.

Then I checked the author's website and saw a lot of

recent

comments by users having the same issue - that the extension just stopped working for them.

Since I've developed a few Chrome extensions myself, I remembered that the changelog between Manifest 1 and 2 includes a new content security policy and also that Manifest 1 was announced deprecated in Chrome 18.

So I checked my Chrome version and saw that it was updated just that morning (from 20.x to 21.0.1180.60 m). Hence, I thought that the exceptions, thrown by the extension, were due to the "fact" that the old content security policy, which was used before Manifest version 2, was unsupported with that Chrome-Update.

So I updated the extension's source code to use Manifest version 2. Finally, I had no more content security policy exceptions in the dev console and the downloads worked again.

And because there was no update by redphx and I've seen a lot of users had the same issue, I thought I'd share it here.

To cut a long story short:

I was wrong in saying that the original extension stopped as of Chrome 20+ due to missing support by Chrome.

However, for me v1.2.1 constantly throws content security policy exceptions in Chrome which prevent it from working at all. And as you can see from the comments on redphx's website it stopped working for others, too (whatever else the reason is..!?).

Also, as you can see from the schedule, v1.2.1 will stop working in the not-too-far-away future (unless redphx will release an update), whereas mine is "future-proof" (as far as it concerns Chrome).

Finally, my version does not include Analytics code, nor does it redirect you to a site which can not be verified to be safe (it should be, though).

No, the developer should be irrelevant.

Now, as I said earlier:

"I used v1.2.1 almost every day and I never had problems to download Apps,

except for a few that were labeled as incompatible with my devices

in the play store."

However, this was not true for all Apps that were labeled as incompatible. Some work, most do not. I'm not really sure how the checks work at this point. I know that there exist options for developers to restrict access to downloads by some "more advanced" parameters (apart from payment, obviously). And I think that the the device compatibility check for the In-App-Listings and the Play Store Website is separated from the logic that is used for those "advanced" restrictions (and no, I'm not talking about the basic country-limit here).

As another weird example take the new chameleon launcher beta. The Play Store says it would be compatible with my device. However, I can not download it. Neither through the Play Store, nor with the extension. Why not? Because, as you can read on the developer's website, your Emailaddress for Play Store must be paired with the Emailaddress that I/someone used in the developer's beta signup form that was on the website a few weeks ago. Means: eventhough it is a free App and labeled as compatible in Play Store, I can not download it because the developer needs to

specifically allow my Account

. As you can see, there're lots of possible and not always understandable reasons why somebody can download some apps while others can't.

I don't think that editing the build.prop file will help with that at all. Even if I change everything in my build.prop, the Useragent that is send by the Play Store App still uses/reveals the real device info. No matter what I change, it always sends: "AndroidDownloadManager/4.1.1 (Linux; U; Android 4.1.1; Nexus One Build/JRO03H)".