Although that may get rid of some bird shit and the worst of the road grime, the glass isn't clean.
Dirty glass collects more dirt as the new sticks to the old. So do it right.
Start with your standard glass cleaner and a few microfibre cloths.
Spray it on and agitate it around the screen. Repeat but with a clean cloth. The result is quite good.
However, it can get better. Get a clay bar kit containing a bar and a quick detailing spray.
Spray the quick detailer on...
...and go over the entire piece of glass with the clay bar. Round and round in circles.
Keep the screen wet with the quick detailing spray. A warm clay bar helps too.
The clay bar is actually a very fine abrasive that lifts impurities and flattens back and loosens any stuck dirt.
When you have finished all of the glass, you'll probably see swirls of dirt in the clay.
Buff all of the quick detailer spray off the glass. Spray isopropyl alcohol (IPA) onto the screen
...and wipe it off with a clean microfibre cloth.
The IPA will evaporate very quickly.
Look at the finished glass. This is a reflection through a side window and everything is totally clear.
This is not a tinted window. It's just incredibly clean. You can see the detail in the reflections.
Now is a very good time to use Aquapel on the windscreen.