Here is how I find and install apps on my phones:
In a browser, open this link to find your app:
For example, you can search for "Notification Auto Clear" and get it at this URL:
Copy the link (URL), open the following link and paste. Then click on "Generate Download Link":
Then click on "generate download link" again, then click on "Proceed to Notification Auto Clear 1.0 (or the app name) apk Download Page". Wait for a few seconds (depending on the size of the app), your browser will pop up the download dialog:
Now your phone will start to download the apk file, once finished, simply click/open it to install the app.
If you did above steps on a computer, then you need to transfer the downloaded apk file to your phone, obviously. Then use a file browser to open/install the apk file. If your phone does not have any file browser yet, then you need to do above steps on your phone for a file browser such as ES File Explorer.
It is not so convenient but well worth it and once you are familiar with the process, it is quite easy.
[update] Another two very easy ways - just open the following URL's on your phone: