Here is a list of good CCD targets for April as well as a list for visual observers able to observe LPVs fainter than 13th mag.
Name Range date of min mag in April
Z PEG
<8.4-13.2>
min(9)
S PSC
<9.6-15.0>
min(8)
W AND
<7.4-13.7>
min(27)
S TAU
<10.2-15.3>
min(3)
U AUR
<8.5-14.0>
min(19)
X GEM
<8.2-13.2>
min(9)
V GEM
<8.5-14.2>
min(20)
S GEM
<9.0-14.2>
min(10)
S SEX
<9.1-13.4>
min(25)
S LEO
<10.1-13.9>
min(5)
R COM
<8.5-14.2>
min(7)
V VIR
<8.9-14.3>
min(3)
R CAM
<8.3-13.2>
min(7)
S SER
<8.7-13.5>
min(12)
R SER
<6.9-13.4>
min(7)
W CRB
<8.5-13.5>
min(28)
V DRA
<9.9-14.2>
min(19)
Z LYR
<10.1-14.8>
min(14)
RU LYR
<10.6-15.1>
min(16)
SY AQL
<9.5-14.4>
min(23)
ST CYG
<9.9-13.9>
min(22)
T DEL
<9.3-14.8>
min(14)
RS AQR
<10.0-14.0>
min(14)
RR PEG
<9.2-14.1>
min(28)
RW PEG
<9.7-14.0>
min(30)