Just to add to Comfy Chair's post...
On some types, like the NG, early stages of flaps can in some cases carry enough drag to slow down on a 3 degree glide slope. On a 737 NG, flap 1 will usually result in speed increasing but if flaps 5 are deployed within placard limits you will be able to stablise the speed and call for more flaps. With a tailwind, flaps 10 might be needed (for some reason most operators see the optimal flaps sequence on that type as 1,5,15 and 30/40, bypassing the very handy flaps 10).
HOWEVER, companies like my employer do not want you to "use flaps to slow down" because it increases flaps maintenance costs. So the want you to select the appropriate flap (typically 5) when intercepting the glideslope, to prevent the speed increasing in the first place.
Even though the speedbrakes will help reduce speed in the early stages of flaps, the NG FCTM says the use of speedbrakes should be avoided when flaps are deployed (but it is not prohibited). So when I see the speed increasing on the glide, I just drop the Dunlops.
Cheers
P