Your Flying units have +1/+1.
Windshaper is a Unit.
How to Get
This card can also be obtained from Card Packs. Diamond Chests and Card Packs can give Premium versions of this card.
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If a Flying unit can't fly due to a Sandstorm Titan effect, it will still get the +1/+1 as long as it still has Flying in its card text.
The +1/+1 bonus will not be applied to units that do not have Flying in their card text.
Your Flying units will lose the bonus when Windshaper leaves play or is Silenced, and if they currently are at 1 Health, will not go below 1 Health when the ability stops.