Will both type cradle booster improve signal on phone, tablet, laptop?

No, neither of the two types of combined cell signal booster and phone holder can boost reception on all 3 devices at the same time. Both of them can only boost a single device at a time. A cradle booster only boosts signals for a device that is placed in the cradle. Connectivity for other devices can be improved by placing a phone in the cradle as a hotspot device. This will allow other devices such as tablets and laptops such as Chrome Book or Mac Book to benefit from the boosted signal if they are using that boosted in-cradle phone's hotspot. The phone must have hotspot capability to be used in this way.

Similarly, a mobile Internet hotspot (MiFi, JetPack, etc) could also be placed in the cradle.

If you need a cell phone signal booster that will boost signal for laptops and tablets as well as phones independently and simultaneously, a wireless in-vehicle cell phone signal booster is probably your best option.