Armed Spell

When you cast a spell as part of the Ready action, you can spend 1 sorcery point to hold the spell's energy without requiring your concentration. If you didn't release the readied spell before the start of your next turn, you regain any spell slot you spent casting it.

You can use Armed Spell even if you have already used a different Metamagic option during the casting of the spell.

Homing Spell

When you cast a spell with a range of Touch or greater, you can spend 2 sorcery points and name one creature within the spell's range or describe it in up to 5 words. If it isn't within the spell's range, the metamagic has no effect.

Being unable to see that creature doesn't stop you from targeting it, and it gains no benefit against the spell from half or three-quarters cover; the spell moves around corners and through spaces as small as 1 foot wide to reach it.

You can use Homing Spell even if you have already used a different metamagic option during the casting of the spell.

Stable Spell

When you cast a spell that requires concentration, you can spend 3 sorcery points to stabilize its magic. Your concentration on that spell can't be broken as a result of taking damage.

Art Credit:
Clint Cearley, WotC