I'm trying to install a large application (EA games' Scrabble free), but I have insufficient space on my phone, so I can't complete the installation. I have plenty of space on my SD card though, but I don't see any option to install the app directly there without passing through the phone. What can I do about this?
You are out of luck sorry!
The only way to do so, is to install to internal space on Phone, then:
Move to SD Card
You will have to free up space temporarily in order to do this.
There is no such option that applies for all apps.You still have to go through your internal memory.
As far as I know rooted phones also don't offer this functionality.
But some apps will allow you to do that on newer phones. App developers can say in their app that it is best (preferred) to save the app on an SD card. But in the case they say that, it's in the hands of the phone if it listens to it or not. So even though some apps will allow you to install it straight on your SD, some phones will still install it on your internal memory.
Though the last part is not an answer to your question, I thought it may be interesting to know
This question already has an answer here:
At least on my phone, it seems you need way more available space thanthe size of the app you are actually trying to upgrade. In my case it seems I needed to have at least ~13MB free space to upgrade anything at all (even for 500KB apps).
Some tips to free space:
In some cases I have also been able to manually update apps one at a time when "update all" fails due to insufficient storage.
I discovered that K9 Mail was keeping 25MB of cached data on my internal storage. I changed it to use the SD card, and this cured my immediate problem of being unable to install a tiny app.
It doesn't explain, though, why Android was reporting an insufficient storage error whilst simultaneously telling me there was 14MB free on internal storage. Oh well.
You are trying to install the .apk from a source other than the root directory. Copy the .apk into the root directory and install it from there.